Automatic elevator system



Dec. 10, 1940. BQUTQN EI-AL 2,224,718

AUTOMATIC ELEVATOR SYSTEM Filed Sept. 5, 1938 4 Sheets-Sheet l fimvhmvgp w a ama n n 1 Q a 3 d 5 nr L.

INVENTORS yar/Mfiaufan and fi a z mona fh aru. BY 3 ATTORNEY WITNESSES:

1360- 1940- E. M. BOUTON ETAL AUTOMATIC ELEVATOR SYSTEM Filed Sept 5, 1958 4 Sheets-Sheet 5 INVENTORS Fa yarMBaufan and fi ayrr ndf Ward ATTORNEY.

WITNESSES:

Dec 10, 1940.

E. M. BOUTON ETAL AUTOMATIC ELEVATOR SYSTEM Filed Sept. 5, 19558 4 Sheets-Sheet 4 New? WITNESSES: 2.472%

Patented Dec. 10, 1940 UNITED STATES PATENT OFFICE AUTOMATIC ELEVATOR. SYSTEM Application September 3, 1938, Serial No. 228,304

6 Claims.

Our invention relates to elevator systems of the type in which the cars are automatically stopped at the floors by suitable apparatus dependent on car position, and particularly to such systems of the type in which the cars are operated at relatively slow speeds of the order of 150 feet per minute or less. Although not limited thereto, our invention is particularly applicable to elevators of the so-called geared-drive type, in which the hoisting sheave is driven through suitable gearing from a constant speed motor, commonly called an induction motor.

The usual motors provided in such installations have a drooping speed-torque characteristic, resulting in some variation of car speed, dependent upon the elevator load. If the motor is disconnected and the brake applied at a fixed distance in advance of a. floor, in the absence of any correcting device the car will coast or drift a variable distance against the retarding torque of the brake, and an accurate stop will result for only one particular value of load.

We have found that, for a particular direction of car movement, accurate stopping may be effected by varying the distance from the floor at which the motor is cut-off and the brake applied, as a substantially linear function of the time required for the car to travel a fixed distance at full speed. In order to effect such accurate stopping, it is necessary to increase the cut-off distance a greater amount the higher the speed of the car.

It is accordingly an object of the present invention to provide a novel elevator system of the type indicated above, in which the distance in advance of a floor at which the brake is applied is varied as a function of the time elapsed by the car in traveling a fixed distance in the hatchway.

Another object of our invention is to provide an elevator system of the type indicated above, in which the distance in advance of the floor at which the brake is applied is varied as a function of the speed of the car in approaching the floor.

In another aspect, it is an object of our invention to provide an elevator system of the type indicated above, in which calls may be registered by means of simplified relay equipment.

Other objects of our invention will become evident from the following detailed description, taken in connection with the accompanying drawings, in which Figure l is a diagrammatic view of a control system embodying our invention;

Fig. 1A is a diagrammatic view showing the mechanical relationship of relay coils and contacts used in the system of Fig. 1;

Fig. 2 is a diagrammatic view of a preferred form of floor selector which may be substituted for the selector in the system shown in Fig. 1

when desired;

Fig. 3 is a diagrammatic view of a detail of the floor selector shown in Fig. 2;

Fig. 4 is an elevational view of an inductor relay and its associated driving motor equipment, as used in the system shown in Fig. 1;

Fig. 5 is a diagrammatic view showing the arrangement of an elevator car and principal mechanical parts associated therewith, of a modification of the system shown in Fig. 1;

Fig. 6 is a diagrammatic view of a modification of the control system shown in Fig. 1, as used with the mechanical arrangement disclosed in Fig. 5; and

Fig. 6A is a diagrammatic View, similar to Fig. 1A, showing the mechanical relationship of relay coils and contacts in the modification shown in Fig. 6.

Referring to Figure 1, in detail, a polyphase induction motor MR is arranged to be connected to a suitable constant voltage polyphase supply source I, by means of either an up direction switch U or a down direction switch D, depending upon the direction of elevator car travel desired.

The induction motor MB. is mounted on a common shaft I3 with a spring-applied, electromagnetically-released brake EB and with suitable gears l4 for driving a floor selector, shown diagrammatically at IS. The shaft i3 is mechanically connected to a driving sheave H from which an elevator car A is suspended by means of a cable ill, the free end of which is secured to a suitable counterweight It. It will be understood that the usual speed reduction gears, interposed between the motor MR and the driving sheave ll have, for simplicity, been omitted from the drawings.

The floor selector l5 may be of any suitable type known in the art for controlling a large number of circuits in accordance with the position of the car with reference to the various floors. Although the floor selector I5 is shown diagrammatically in Fig. 1, we prefer to use a floor selector having 5 ecific mechanical features which will be described in connection with Figs. 2 and 3.

A push button panel C is mounted within the car A to permit the registration of calls for various floors from within the car. A stopping inductor SI is mounted upon the car in any suitable position, preferably at the top of the car, for cooperation with suitable inductor plates PU4, PU3, etc., secured in the hatchway in such positions as to cooperate with the stopping inductor. SI when the car is at a suitable slowdown distance in advance of the corresponding floor.

The stopping inductor relay SI is provided with an incomplete magnetic circuit which is completed by the inductor plates PUB, etc., when the car floor is at a suitable stopping distance in advance of the corresponding landing floor. The stopping inductor SI is provided with back contacts SIR, which are normally closed when the inductor relay operating coil is energized and the incomplete magnetic circuit of the relay is not in operating position with reference to an inductor plate such as P114, and are also closed when the operating coil of the relay is deepergized. However, when the magnetic circuit of the relay is completed by an inductor plate, and the relay operating coil is energized, the contacts SII open and remain opened notwithstanding that the relay'may move away from the inductor plate which completed its magnetic circuit, until the operating coil of the relay is deenergized.

Referring to Fig. l, a pair of direct current supply conductors Ll, L2 is arranged to be con nected to the alternating current supply I, in series with suitable rectifiers indicated at 3, by means of a manual switch 2.

A plurality of upcall relays 311R, EUR and EUR are provided for registering calls for service in the upward direction. Each of the relays 3UR, ZUR, etc., may be energized upon operation of either a floor button 3U, for example, for the third floor and the up direction, or upon operation of a car button such as 30, located in the car,

which latter button serves to register a call for both directions of car travel.

A plurality of down call relays lDR, 313R and 213R, controlled similarly to the up call relays 313R, etc., by means of floor push buttons iDB, etc., and car button G0, are provided for regis- 1tering calls for service in the downward direcion.

An up collective relay UA, and a down collective relay DA, are provided for maintaining circuits of the system prepared when a car is stand ing at a floor, and registered calls exist for floors beyond the car in its last direction of car travel in arriving at the floor. The up collective relay UA and the down collective relay DA are controlled by contacts such as 4DR3 of the call refloor, for a sufficient interval of time to permit opening of the car gate and hatchway door. For this purpose the relay VT preferably is designed so that its back contacts VT! and VTZ open substantially instantaneously upon energization of its operating coil, but that the back contacts VTI and VTZ are delayed for a time interval of the order of l to 2 seconds after deenergization of the relay operating coil before reclosing.

A motor reversing relay V is provided for controlling the direction of rotation of an auxiliary motor or inductor driving motor IM (to be hereinafter described in connection with Fig. i),

which serves to control the position of the stopping inductor relay SI in accordance with the time required for the car A to traverse a fixed distance in the hatchway, as will be hereinafter more fully explained. The inductor driving motor IM is preferably of shunt type having a shunt field winding IMF (Fig. 1) connected to the sup ply conductors L! and L2 and having its armature IMA control ed by contacts of the motor reversing relay V.

A stopping relay DC is provided for initiating automatic stopping operations at floors for which calls are registered on any of the call relays 4BR,

etc.

The construction of certain mechanical elements involved in the invention is shown in Figs. 2, 3 and 4. Referringto Fig. 2, a preferred form of floor selector I5 is illustrated diagrammatically therein. A threaded shaft ii, the rotation of which is determined'by any suitable mechanism, such as the gears M of Fig. 1, or a separate selector motor SM (Fig. 2) in accordance with the position of the car, is arranged to drive a traveling nut 22. The traveling nut 22 carries a roller 23 which is positioned to sequentially engage a number of contact assemblies i l, 2%, etc., situated at various points in the path of movement of the roller 23, corresponding to car positions at which circuits are to be cornmutated. Although only four such contact assemblies 24, 25, etc, are shown in Fig. 2, it will be understood that in practice a large number would actually be provided, dependent upon the number of floors and the number of contact operating positions between floors, involved in the particular installation in question.

Referring to Fig. 3, a preferred construction of the contact assemblies 24, etc., is shown therein. The contact assembly preferably comprises a number of contact springs 35, BI, 32, etc., of resilient flexible material, separated by sheet insulation 37, and secured by suitable fastening members 38 to constitute a compact unit. The contact springs 30, etc., cooperate in pairs to control suitable front contacts such as i-K and back contacts such as 4A.

An operating stud 34 is mounted on the uppermost contact spring 3@ in position to be engaged by the roller 23, and suitable intermediate studs 35 and 33 are provided for operating the contact springs for the lower pairs of the assem bly, in response to engagement of the operating stud 34 with the roller 23. It will be understood that as the roller 23 engages the operating stud 34 of any particular contact assembly, all of the front. contacts of the assembly, such as thecontacts 4K, are closed and all of the back contacts of the contact assembly, such as contacts 4A and 4--B are opened.

Referring to Fig. 4, which shows the mechanical arrangement of the stopping inductor relay SI and its associated inductor driving motor 1M, a relay panel 40 is secured to a suitable part of the car A, such as the upper part of the frame 4!, by means of suitable brackets 62 and 43 and bolts 44 and 45. A reciprocable relay carriage 46 is mounted upon the relay panel 43 and provided with suitable guide rollers 51 in such ma-.- ner that it may be moved freely in the vertical direction with reference to the car.

The relay carriage 46 is arranged to be driven in the upward or downward direction by the inductor driving motor IM acting through the intermediary of a threaded shaft 48 which cooperates with a suitable traveling nut 41 secured to the relay carriage 46. The threaded shaft 48 is journalled at its lower end in a suitable bearing 49 mounted upon the relay panel 40.

The stopping inductor relay SI is secured to the relay carriage 46 so as to move therewith, and a roller 53 is carried by the carriage 46 to engage either an upper limit switch ITI or a lower limit switch IBI at the limits of movement of the relay. A similar upper limit switch 1T2 and lower limit switch IE2 (not shown) are pro vided and controlled in the same manner as the limit switches IT! and IBI.

The connections for the stopping inductor relay SI are brought out by means of a cable 54 to a relay terminal panel 55, from which connections may be made to the usual cable carried by the car.

The operation of the apparatus shown in Fig. 1 may be set forth as follows, assuming initially that the car A is at the first floor and that the manual switch 2 is closed.

Assuming that a prospective passenger at the fourth floor operates the call button 4DB, a circuitis completed for the call relay 4BR which may be traced as follows:

Upon completion of the latter circuit, the call relay 4BR closes to complete .a holding circuit for itself by means of its contacts 4DRI; to prepare a circuit for subsequent energization of the stopping relay DC by means of its contacts 4DR2 and to complete a circuit for the up collective relay UA by means of its contacts 4DR3. The latter circuit may be traced as follows:

Upon completion of the latter circuit, the up collective relay UA closes and completes a common energizing circuit for the up direction switch U and the running relay M by means of its contacts UAI and also prepares the circuits of the time delay relay VT and the motor reversing relay V for subsequent operation by means of its contacts UAZ. The up collective relay UA, in closing, also opens its back contacts UA3 in the circuit of the down collective relay DA, thereby preventing energization of the latter relay while the up collective relay UA is closed.

The common circuit of the up direction switch U and the running relay M, mentioned above, may be traced as follows:

In response to completion of the latter circuit, the up direction switch U and the running relay M close. The up direction switch U, in closing, completes an energizing circuit for the induction motor MR by means of its contacts UI and U2; completes a holding circuit for itself by means of its contacts U3; completes a common energizing circuit for the time delay relay VT and the motor reversing relay by means of its contacts U5; connects the relay Winding EBW of the brake EB for energization by means of its contacts U5; and connects the armature IMA of the inductor driving motor IM for operation in connection with a run of the car in the up direction, by means of its contacts U8 and U9. The up direction switch U, in closing, also opens its front contacts U4 in the circuit of the down direction switch D, to thereby prevent energization of the latter switch while the up direction switch U is closed; closes its contacts U! to prepare the stopping relay DC for subsequent energization; and short circuits the lower limit switch IBI and the upper limit switch ITZ of the stopping inductor relay SI by means of contacts Ulll and UH. The running relay M, in closing, establishes a shunt circuit around the floor selector contacts 4--A, 3-B, etc., in the circuit of the call relays 4DR, etc., by means of its contacts Ml, M2, M3 and M5. The running relay M, in closing, also completes a circuit for the operating coil of the stopping inductor relay SI by means of its contacts M4.

The common energizing circuit for the time delay relay VT and the motor reversing relay V, completed upon closure of the up direction switch U, may be traced as follows:

In response to completion of this circuit, the time delay relay VT becomes energized to open its contacts VT! and VTZ in the closing circuits of the direction switches U and D. As the direction switch U is held in through a holding cir cuit completed by its contacts U3, the operation of time delay relay VT is without effect at this time.

As mentioned above, the motor reversing relay V is also closed in response to closure of the up direction switch U. The motor reversing relay V, in closing, interrupts the circuit of the operating coil of the stopping inductor relay SI by means of its contacts VI; and also determines the direction of rotation of the inductor driving motor IM by means of its contacts V2, V3, V4 and V5.

With the direction switch U and the motor reversing relay V both closed, the connections of the inductor driving motor IM are such that the inductor relay SI is moved in the up direction if the relay is not already at its upper limit of travel. Assuming that the inductor relay is at its lower initial position, then the switches IBI and 1132 are open and the energized switch U and the relay V energize the inductor driving motor armature IMA to move the inductor relay SI upwardly, by the circuit:

Ll, U8, ITI, UH], V3, IMA, V4, U9, L2.

The movement of the stopping inductor relay SI at this time carries the latter upward to its upper limit of movement, at which point the limit switch IT! is opened to prevent further relay movement and the relay SI now remains in its upper initial position.

As the induction-motor MR. is now connected for energization to the supply circuit l, and as the brake EB is released, the car A is started in the upward direction and accelerates. to full speed in a short distance of car travel.

Assuming that a prospective passenger at the second floor registers a call for upward service by operating the push button ZUB at the second floor, a circuit, is completed for'the call relay ZUR, similar to that traced above for the call relay 4DR. The call relay 2UR, accordingly, closes to complete a holding circuit for itself by means of its contacts ZURI; to prepare an additional circuit for the stopping relay DC by means of its contacts ZURZ; and to prepare an additional circuit for the up collective relay UA by means of its contacts 2UR3. It will be recalled that a similar circuit for the stopping relay DC has already been prepared by contacts 4DR2 of the call relay 4DR.

As the car moves upward toward the second floor, it passes a point in advance of the floor at which the normally open floor selector contacts 2E and 2F are closed. Closure of the selector contacts 2-E is without effect at this time but closure of the selector contacts 2F completes a circuit for the stopping relay DC which circuit may be traced as follows:

In response to completion of the latter circuit, the stopping relay DC operates to open its contacts DCI, thereby effecting deenergization of the time delay relay VT and the motor reversing relay V, and to complete a holding circuit for itself by means of its contacts DCZ. contacts D03 of the relay DC also close at this time but are without effect, except in the preparation of circuits for subsequent energization.

The motor reversing relay V, upon deenergization, completes a circuit for the energizing coil of the stopping inductor relay SI by closing of its contacts VI; and opens its contacts V3 and V4 and closes its contacts V2 and V5 to reverse the connections of the armature IMA of the inductor driving motor IM, so as to cause the latter motor to drive the stopping inductor relay SI in the downward direction. The armature circuit extends:

Ll, U8, Ul l, 1B2, V5, IMA, V2, U9, L2.

The distance in the hatchway between the position of the car at which the floor selector contacts 2F close, and the position of the car when its platform is level with the second floor is a constant, and as the inductor relay SI is being driven downward at constant speed, the time which will elapse before the car reaches the second floor is a function of its initial velocity.

As the car speed will be quite high with light loads, for example, it will be seen that the interval of time required to reach the floor will be short, so that the stopping inductor relay SI will, under these conditions, be near its upper limit when the car platform nears the level of the second floor. If, on the other hand, the car carries a heavy hoisting load, its speed will be relatively low, and the time available for driving the stopping inductor SI in the downward direction at constant speed will be increased. Under the latter conditions, accordingly, the inductor relay SI will be moved to a lower position, and the slowdown distance decreased.

When the stopping inductor relay SI arrives at a position opposite to the inductor plate (not shown) provided for stopping of the car in the upward direction at the second floor, the magnetic circuit of the stopping inductor relay SI is completed, and the latter relay operates to open the common energizing circuit of the up direction switch U and running relay M by means of its contacts SII.

Upon interruption of the common energizing circuit of the up direction switch U and the running relay M, the switch U and relay M drop out. The up direction switch U in dropping out, disconnects the induction motor MR; interrupts the energizing circuit of the brake release winding EBW; and opens its contacts U8 and U9 to deenergize the armature IMA of the inductor driving motor IM. The up direction switch U also opens its contacts U! at this time, thereby interrupting the circuit of the stopping relay DC and restoring the. latter relay to deenergizing condition. The running relay M in opening, removes the shunt circuit around the floor selector contacts 4A, etc., in the circuits of the call relays 4BR, etc.

As the elevator motor MB is now disconnected, and the brake EB is applied, the car A decelerates car loads.

The front or'drifts against the retarding torque provided by the brake EB, to the second floor. As the braking distance has been adjusted by the position of the stopping inductor relay SI in accordance with the car speed, the amount by which the car A drifts against the action of the brake is exactly sufficient to bring the car to floor level. The amount of drift required to arrest the movement of the car is different for different car speeds and In a typical installation, the distance of drift might be 6 to 8 inches, for example.

Upon arrival of the car at the second floor, the floor selector contacts 2-'A and 2B are opened, as are the floor selector contacts 2-C and 2D. In response to opening of the selector contacts 2A and 2B, the call relays ZDR and ZU'R, for the second floor are completely disconnected, and it is impossible to register calls on these relays until the car has moved away from the second floor. The opening of the floor selector contacts 2C and 2-D is without effect at this time as the circuit of the up collector relay UA is maintained through contacts 4DR3 of the call relay As the car is now standing at the second floor, the operator must open the gate within a short time interval to prevent restarting of the car when the time element of the time delay relay VT expires. Itwill be recalled that the time delay relay VT was deenergized upon closure of the stopping relay DC, but as the time element of the relay VT is of the order of 1 to 2 seconds, sufficient time is available for opening the car gate before operation of the latter relay to close its contacts.

' When the prospective passenger at the second floor has boarded the car, the operator may close the hatchway door and car gate, thereby completing a circuit for the up direction switch U and running relay M, similar to that traced above.

The up direction switch U, accordingly, again closes to complete a circuit for the time delay relay VT and the motor reversing relay V and to establish connections of the inductor driving motor IM in the manner described above, thus causing the motor IM to return the inductor relay SI to its upper position ready for the next stop. The running relay M also again closes to establish shunts around the A and B contacts of the floor selector in the circuit of the call relays 4DR, etc.

Car A, in response to closure of up direction switch U, starts in the upward direction in the manner previously described. As the car leaves the second floor, the floor selector contact 2A, 2B, 2C and 2D all close. The closure of contacts 2--A and 2B prepares the circuits of call relays BUR and ZDR for the second floor, so that calls can now be registered upon these relays.

As the car approaches the position, in advance of the third floor, at which the floor selector contacts 3--E and 3-F close, the latter contacts are momentarily operated but are without effect at this time.

Similarly, as the car passes the third floor, the floor selector contacts 3A, 3-B, 3C and 3-D are momentarily opened and reclosed.

Further upward movement of the car toward the fourth floor brings it toward the position in which the floor selector contacts i-E close. Upon arrival of the car at the latter position, a circuit is completed for the stopping relay DC, and the latter relay closes to drop out the time delay relay VT and the motor reversing relay Vin the manner described above. The motor reversing relay V, in dropping out again causes the stopping inductor relay SI to be driven in the down direction at constant speed, and upon movement of the latter inductor relay through a variable distance dependent upon the initial velocity of the car, the up direction switch U and the running relay M are again opened in the manner described above. The car accordingly drifts into the fourth floor against the action of the brake as described above in connection with the stop made at the second floor.

Figs. 5 and 6 illustrate another manner of applying the invention in which the inductor relay SI is provided with only one stopping plate at each floor and an auxiliary inductor relay Y is mounted on the car for causing operation of the floor selector motor SM. In this application, the inductor relay SI is provided with only one stopping plate for each floor. This stopping plate is effective for both directions of operation of the car. The plates are indicated as SP4 for the fourth floor, SP3 for the third floor, SP2 for the second floor, and SPI for the first floor. The stopping plates should be mounted in position on the hatchway walls (not shown) in accordance with the position of the inductor relay SI on the car. Inasmuch as the selected speeds of the car, the weight of the car, .etc., vary with each in stallation, the positions of the plates and the relay must be selected in accordance with the conditions under which they are used.

The auxiliary relay Y is provided with an up magnetic circuit and a down magnetic circuit and is disposed to be operated by up inductor plates UF2, UF3 and UF4 at the corresponding floors for up car travel and by down plates DF3, DF2 and DF! at the corresponding floors for down car travel. These plates are mounted on the hatchway walls and should be so positioned that the up plate for a floor will, when the car brings the auxiliary relay opposite it, operate that relay to cause the motor SM to move the floor selector arm from the contacts for the previous fiOOI to the contacts at the floor of the plate. Furthermore, the position of that plate with reference to its floor should be at the point where movement of the inductor relay SI should start to enable it to move to the correct position on the car to cause it to deenergize the hoisting motor and apply the brake when it passes the stopping plate so that the length of drift of the car will be in accordance with the speed of the car.

Inductor relays having a plurality of magnetic circuits are illustrated and described in the White 8: Hearn Patent 1,884,446, issued October 25, 1932, to which reference may be had if details as to such relays are desired.

A pair of up contacts YU and a pair of down contacts YD are mounted on the relay Y to be operated by the up magnetic circuit and the down magnetic circuit, respectively. The inductor relay Y also differs from the stopping inductor relay SI heretofore described, in that its contacts YU and YD open momentarily when the relay coil is energized while an inductor plate for the corresponding direction of car travel is passed, but immediately reclose as soon as the inductor plate is passed. The contacts YD, for example, accordingly close momentarily each time a down inductor plate, such as D3 or D2, is passed during downward movement of the car for controlling the movement of the floor selector SM. The armature of the selector motor SM is controlled by means of a starting relay NA and a pair of driving relays NB and NC.

Otherwise, the operation of the modification shown in Figs. 5 and 6 is similar to that described above in connection with Fig. 1.

Referring to Figs 5 and 6, the operation of the apparatus shown therein may be set forth as follows:

Assuming that the car is at the fourth floor, and that the relays NB, NC and NA stand energized by reason of the movement of the car into that floor, and that the motor SM is deenergized because the contacts NAI are open. The circuit for the relay NB extends: Ll, 4G, NB, L2.

The circuit for the relay NC extends: Ll, YD, UM, NCI, NC, L2.

The circuit for the relay NA extends: Ll, NC2, N132, NA, L2.

As the car is now operated downward from the fourth floor in the manner described in Fig. 1,

the down direction switch D operates to open its contacts DH in one side of the parallel circuit leading to the motor armature SMA and to the starting relay NC, thus leaving this circuit in the control of the contacts YD. Switch D also closes its contacts D|5 and D16 in the circuit of the selector motor armature SMA, but the motor SM cannot yet be energized because contacts NAI are still open. I

As the car approaches the third floor in its downward movement, the auxiliary inductor relay Y arrives at a position opposite the inductor plate DF3 in the hatchway, which is positioned at a point in advance of the third floor, where the selector motor SM should move the selector arm SA from the fourth floor contacts to the third floor contacts. When this occurs, the inductor relay Y momentarily opens its contacts YD in the remaining side of the parallel circuit to interrupt the circuit of the driving relay NC, and the latter relay opens its contacts N02 to interrupt the circuit of the starting relay NA.

Upon deenergization of the starting relay NA, the latter operates to close its contacts NA! and thereby completes a circuit for the selector motor armature SMA, extending: Ll, YD, UH, RI, DIS, DIB, NAI, L2.

It will be apparent that this is possiblebecause the contacts YD reclose as the car passes the plate DF3.

As the selector motor SM is now energized, it drives the traveling nut, or other movable element of the floor selector I5A, in the direction corresponding to downward car movement until it closes selector switch 3G to stop the selector motor with the floor contacts for the third floor in operated condition. Upon initial movement of the floor selector traveling nut from the position corresponding to the fourth floor, the floor selector contacts 4-G are opened, thereby causing the driving relay NB to drop out. The driving relay NB, in dropping out completes a circuit for the driving relay NC by means of its contacts NBI, and the driving relay NC accordingly closes.

Upon further movement of the traveling nut of the floor selector ISA in the direction corresponding to downward car motion, the selectorcontacts 3-G close, completing a circuit for the driving relay NB, thereby again energizing that relay. As the driving relays NB and NC -are both closed, a circuit is again completed for the starting relay NA, and the latter relay again operates to interrupt the circuit of the armature SMA. The selector motor SM, accordingly, is deenergized in such position that the movable element of the floor selector I5A is in the position corresponding to the third floor.

floor.

By this operation,it will be seen how the movement of the car from one floor toanother carries the auxiliary relayY past the inductor plate for the nextfloor and thereby actuates the inductor relay Y to cause the selector arm SA to move from its contacts for one floor to its contacts for the next floor. It will also be apparent that the relay Y inductor plate for a floor may be so positioned in advance of that floor that it will cause the relay Y to actuate the floor selector to close the floor contacts (say, 3E in Fig. l) to start inductor relay SI from its normal initial position on the car and move it at constant speed until the car arrives at the point where the inductor relay SI is operated by its inductor plate to stop the car.

7 It will be apparent from the above that as each floor is approached, the selector motor SM is energized for the period of time required to drive the selector movable element to the position corresponding to the nextfioor in advance of the car in its direction of travel.

Returning now to the car as it was standing at the fourth floor, it will be assumed that a waiting down passenger at the third floor pressed the hall button 3DB for a down stop at that This operation of the button SDB energizes the call registering relay 3BR to start the car from the fourth floor and stop it at the third floor in practically the same manner as described inmoving the car from the first door to the second floor. However, in the application shown in Figs. 5 and 6, only one stopping plate is provided lay VT and the reversing relay V. Atthis'point,

it will be assumed that the inductor relay SI was moved to its lower initial starting position by the closing of the down switch contacts DH) when the car was started down in the same manner as it was moved to its upper initial position by the closing of the up switch contacts Uill when the car was described as leaving the first floor. Under these conditions, the deenergization of the relay V closes its contacts V2 and V5, thus energizing-the motor IM to move the inductor relay SI upwardly on the car at a constant speed while the car itself is moving down close to the third As the car nears the third floor, the inductor relay SI comes opposite the stopping plate SP3 (Fig. 5) and is thereby operated to open its contacts SII, which in turn, deenergize the down direction switch D and the running relay M to stop the hoisting motor MR and apply the brake EB in the same manner as previously described be moved a greater distance upwardly on the car while'it moves down toward the third floor than it would if the car were running fast, and hence, the inductor relay will not reach the stopping plate SP3 until the floor of the car is nearly at the level of the third floor, and cutting oil the power and applying the brake at this point will give the brake the correct distance for stopping the car with its floor level with the third floor.

By the foregoing description, it will be apparent that, with the proper location of the auxiliary inductor plates DF3, etc., in advance of the floors and the use of the stopping inductor SI, the car will bestopped level with the landing floors, regardless of its speed as it approaches-a stop.

We do not intend that the present invention shall be restricted to the specific structural details, arrangement of parts, or circuit connections herein set forth as various modifications thereof may be effected without departing from the spirit and scope of our invention. We desire, therefore, that only such limitations shall be imposed as are necessitated in the appended claims.

'We claim as our invention:

1. In an elevator system, an elevator car operable to serve a landing floor in a hatchway, a hoisting motor for the car, a switching device movably mounted on the car, motive means fixed on the car for moving the switching device, means responsive to operation of the car for causing the motive means to move the switching device to an initial position, means for operating the switching device when that device is at a predetermined point in the hatchway for a stop at the floor, means responsive to the car passing a selected point in advance of said predetermined point in making a stop at the floor for energizing the motive means to move the switching device from its initial position at a constant speed whereby the relative position of the car and the switching device when the switching device reaches said predetermined point will be proportioned to the speed of the car, and means responsive to operation of the switching device as it reaches said predetermined point for deceleratingthe car, whereby the deceleration of the car is effected while the car is a distance from the floor proportioned to the speed of the car.

-2. In an elevator system, an elevator car operable to serve a floor landing in a hatchway, a hoisting motor for the car, means for decelerating the hoisting motor including a switching device movably mounted on the car, control means for starting the motor and for initiating operation of the decelerating means, motive means fixed on the car for moving the switching device, means responsive to operation of the control device to start the car for causing the motive means to place the switching device in an initial position foroperation whenthe motor is to be decelerated, means responsive to operation of the control device to initiate operation of the decelerating means and to the switching device passinga predetermined point in the hatchway in advance of the floor for operating the switching 2 ,means responsive to operation of the car for the switching device reaches said predetermined point so as to efiect deceleration of the motor when the car is at a distance from the floor proportioned to the speed of the car.

3. In an elevator system, an elevator car operable to serve a landing floor in a hatchway, a hoisting motor for the car, a first switch-member movably mounted on the car, an auxiliary motor fixed on the car for moving said first switch-member vertically at constant speed,

causing the auxiliary motor to move the switch member to a normal position While the car is running at high speed, a second switch member mounted in the hatchway in position to effect operation of said first switch-member at a predetermined point in advance of the landing fioor, means responsive to operation of said first switch-member for decelerating the car, and means effective when said car passes a predetermined point in advance of said second switchmember for energizing the auxiliary motor to move said first switch-member from its normal position at constant speed, whereby the relative vertical position of the said first switch-member and the car causes said first switch-member to be operated by the said second switch-member when the car is at a distance from the landing floor proportionate to the speed of the car.

4. In an elevator system, a car operable to serve a landing floor in a hatchway, a hoisting motor for the car, a brake, an inductor relay movably mounted on the car, an auxiliary motor fixed on the car for moving the relay vertically at constant speed, means responsive to operation of the car for causing the auxiliary motor to move the switching device to an initial position for the direction of the car, an inductor plate mounted in the hatchway in position to effect operation of the relay at a predetermined point in advance of the landing floor, means responsive to operation of the inductor relay for decelerating the hoisting motor and for effecting application of the brake to stop the car, and means responsive to the car passing a predetermined point in advance of the inductor plate for starting the auxiliary motor to move the relay from its initial position at constant speed in opposite direction to the movement of the car whereby the relative vertical position of the relay and the car as the relay comes opposite the inductor plate will be in proportion to the speed of the car so that the distance of the car from the landing floor when the relay is operated will be proportionate to the speed of the car.

5. In an elevator system, an elevator car operable to serve a landing floor in a hatchway, a hoisting motor for the car, a control means for starting the hoisting motor, a brake, an inductor relay movably mounted on the car, an auxiliary motor fixed on the car for moving the relay vertically at constant speed, means responsive to operation of the control means in starting the hoisting motor for causing the auxiliary motor to move the relay to a predetermined upper or lower initial position in accordance with the direction of operation of the car, an inductor plate mounted in the hatchway in position to effect operation of the relay at a predetermined point in advance of the landing floor, means responsive to operation of the inductor relay for decelerating the hoisting motor and for effecting application of the brake to stop the car, and means efiective when said car passes a predetermined point in advance of the inductor plate for energizing the auxiliary motor to move the relay at constant speed from its initial position, whereby the position of the relay on the car when the relay reaches the inductor plate causes it to be operated to decelerate and stop the car when the car is at a distance from the landing floor proportionate to the speed of the car.

6. In an elevator system, an elevator car operable to serve a landing fioor in a hatchway, a hoisting motor for driving the car, a control means for starting the hoisting motor, a brake, a carriage movably mounted on the car, an auxiliary motor mounted on the car, a screw-threaded shaft disposed for operation by the auxiliary motor to move the carriage vertically at a constant speed, an inductor relay mounted on the carriage for vertical displacement from an up or a down initial position in accordance with operation of the shaft, means responsive to operation of the control means to start the hoisting motor for operating the auxiliary motor to place the carriage and relay in their initial position in accordance with the direction of operation of the car, an inductor plate mounted in the hatchway in position to effect operation of the relay at a predetermined point in advance of the floor, means responsive to operation of the inductor relay for effecting deceleration of the hoisting motor and application of the brake to stop the car, and means effective when said car passes a predetermined point in advance of the inductor plate for energizing the auxiliary motor to move the carriage and relay at constant speed opposite to the direction of movement of the car whereby the relative speed of the car and the relay will cause the relay to be operated by its inductor plate to cause the deceleration of the car to start at a distance from the landing fioor proportionate to the speed of the car.

EDGAR M. BOUTON. RAYMOND E. WARD. 

